Preparation of organoaluminum compounds

ABSTRACT

IMPROVEMENTS IN PROCESSES FOR PRODUCING ORGANOALUMINUM COMPOUNDS ARE DESCRIBED. THESE IMPROVEMENTS INVOLVE THE USE OF PARTICULAR ALUMINUM ALLOYS AS A SOURCE OF ALUMINUM IN THE PROCESSES. IN PARTICULAR, THE ALUMINUM ALLOYS CONTAIN ABOUT 50-98 PERCENT BY WEIGHT OF ALUMINUM AND AT LEAST THREE OF THE ELEMENTS COPPER, IRON, LEAD, MANGANESE, NICKEL, SILICON AND TIN, THE TOTAL QUANTITY OF SAID ELEMENTS BEING ABOUT 0.75 TO 20 PERCENT BY WEIGHT, THE QUANTITY OF SILICON PRESENT BEING 0 TO 10 PERCENT BY WEIGHT.

United States Patent 3,576,832 PREPARATION OF ORGANOALUMINUM COMPOUNDSWarren E. Becker and Paul Kobetz, Baton Rouge, La., assignors to EthylCorporation, New York, NY. No Drawing. Filed Apr. 24, 1968, Ser. No.723,911 Int. Cl. C07f /06 U.S. Cl. 260--448 10 Claims ABSTRACT OF THEDISCLOSURE Improvements in processes for producing organoaluminumcompounds are described. These improvements involve the use ofparticular aluminum alloys as a source of aluminum in the processes. Inparticular, the aluminum alloys contain about 50-98 percent by weight ofalumi num and at least three of the elements copper, iron, lead,manganese, nickel, silicon and tin, the total quantity of said elementsbeing about 0.75 to percent by weight, the quantity of silicon presentbeing 0 to 10 percent by weight.

This invention relates to the production of organoaluminum compounds.More particularly, this invention relates to the use of aluminum alloysas a source of aluminum in processes for producing organoaluminumcompounds.

Processes wherein an organoaluminum compound is produced by reactingaluminum with an organoaluminum compound and hydrogen or with olefin andhydrogen in the presence of an organoaluminum compound are well known.See for example U.S. 2,787,626; 2,900,402; 2,930,808; 3,000,919;3,016,396; 3,032,574 3,207,770; 3,207,772; 3,207,773 and 3,207,774.

U.S. 3,104,252 discloses the addition to commercially available aluminumof certain catalytic elements viz., titanium, zirconium, niobium,vanadium, hafnium, scandium, and uraniumand the use of the resultantalloys for preparing organoaluminum compounds. In British Patent1,044,735 the production of organoaluminum compounds usingaluminum-silicon binary alloys containing more than 13 percent by weightof silicon is disclosed.

In accordance with the present invention, organoaluminum compounds areproduced by reacting aluminum with an organoaluminum compound andhydrogen or with olefin and hydrogen in the presence of anorganoaluminum compound employing as aluminum feed to the process analuminum alloy containing about 50 to 98 percent by weight of aluminumand at least three of the elements copper, iron, lead, manganese,nickel, silicon and tin. The total qauntity of said elements present isabout 0.75 to 20 percent by weight and the quantity of silicon whenpresent is up to 10 percent by weight. These aluminum alloys are usuallyemployed in subdivided form. Thus, the aluminum alloys used pursuant tothis invention will generally be in the form of turnings, chips,powders, shavings, flakes, chunks, filings, or other type of relativelysmall pieces or fragments.

The reactivity of any given form of these alloys in the process is asgood as, if not better than, the reactivity of the corresponding form ofcommercially available aluminum. As brought out in U.S. 3,104,252, thepurity of commercially available aluminum corresponds to about 99.4percent aluminum, although nowadays even higher purity grades ofaluminum are commercially available.

It will be noted from Table VI of U.S. 3,104,252 that each of theelements copper, iron, lead, manganese, nickel, silicon and tin, whentested individually in a highly pure aluminum-titanium alloy was foundto be a negative Patented Apr. 27, 1971 the patentees teach (column 2,lines element and that 40-42 By inference, then, we believe that theseelements show a retarding or negative elfect on the aluminum.

In the case of silicon the foregoing teachings of U.S. 3,104,252 arereinforced by results reported in British 1,044,735 which show thataddition to aluminum of amounts of silicon up to about 12 or 13 percentgave unfavorable results as compared to the use of aluminum itself as araw material in the manufacture of organoaluminum compounds.

It is also worth noting that from the information tabulated in column 10of U.S. 3,104,252 it would not be expected that the alloys used in thisinvention would react at all.

Another feature of this invention is that the aluminum alloys utilizedas feed in the process tend to be quite inexpensive, oftentimes muchless expensive than regular commercially available aluminum. Moreover,it is not necessary to add one or more of the catalytic elementstitanium, zirconium, niobium, vanadium, hafnium, scandium, and uraniumdisclosed in U.S. 3,104,252, which catalytic elements themselves tend tobe expensive. However, one or more such elements may be present in thealloys used pursuant to this invention.

As noted above, the aluminum alloys used pursuant to this invention as asource of aluminum in the above noted processes contain about 50 to 98percent by weight of aluminum and at least three of the elements,copper, iron, lead, manganese, nickel, silicon and tin. Another featureof these alloys is that the total quantity of these elements presentranges from about 0.75 to 20 percent by weight, the quantity of silicon,if present, not exceeding about 10 percent by weight. Thus, the aluminumalloys utilized pursuant to this invention may contain 3, 4, 5, '6 or 7of these elements although from the standpoint of cost and availabilityalloys containing at least six of these elements are generally mostpreferable. By the same token, aluminum alloys containing all seven ofthese elements are especially preferred.

Insofar as aluminum content is concerned, preferred alloys for use inaccordance with this invention are those which contain about to 98percent by 'weight of aluminum as they contain a high proportion ofaluminum and are available from various existing commercial sources.Particularly preferred alloys contain about to 96 percent by weight ofaluminum.

The total quantity of three or more of copper, iron, lead, manganese,nickel, silicon and tin is about 0.75 to 20 percent by weight, althoughit is usually preferable that this quantity fall Within the range of0.75 to 12 percent by weight. Particularly preferred are alloyscontaining from about 1 to about 10 percent of three or more of theseelements. And in all cases, the greater the number of these elementspresent, the more preferred is the alloy.

From the cost effectiveness standpoint it is usually desirable to usealloys wherein three or more of the foregoing elements are present up tocertain maximum respective quantities as follows:

all of the percentages being expressed by weight. From a practicalstandpoint the alloys will contain three or more of the followingelements within the following ranges or proportions:

Element: Weight percent Copper 0.1- Iron 0.1-2.5 Lead 0.1-1.5 Manganese0.05-3 Nickel 0.05-25 Silicon 0.1- Tin 0.05-1

It will be understood and appreciated that still other elements may bepresent in the aluminum alloys employed in accordance with thisinvention. For example, besides containing aluminum and at least threeof the elements copper, iron, lead, manganese, nickel, silicon, and tin,the alloys may contain one or more other common alloying elements orimpurities such as zinc, magnesium, titanium, boron and the like.Ordinarily the amounts of these other elements present will varye.g.,titanium, if present, will usually not be in excess of about 0.15percent and the amount of zinc, if present, will normally range up toabout percent. The character of the variety of aluminum alloys which maybe used in the practice of this invention will become even furtherapparent from the illustrative examples set forth hereinafter.

The aluminum alloys employed pursuant to this invention may be made byconventional metallurgical techniques and many such alloys are availablefrom a wide variety of commercial sources at exceedingly low cost. It isnot necessary that the composition of the aluminum alloy fed to theprocess be uniform. Indeed, a feature of this invention is that aplurality of different aluminum alloys may be fed to the process with orwithout purer forms of aluminum provided that the overall composition ofthe feed averages out in accordance with the proportions describedabove.

Another feature of this invention is the fact that it enables theeconomical recovery of certain desirable metals from sources in which itis customarily found. By way of example, typical aircraft aluminum alloycontains significant quantities of zinc and copper along with lesserquantities of magnesium, manganese, iron, silicon and chromium. Use ofsuch alloy in accordance with this invention makes possible the recoveryof these elements, especially the zinc, copper and manganese values.

When conducting the processes of this invention it is desirable that thereaction system contain an alkali metal catalyst. These catalystsshorten the induction time of the reaction and also tend to speed up thereaction rate. The nature of many of these alkali metal adjuvants andthe modes by which they are employed are fully discussed in the priorart. See for example US. 2,892,738; 3,026,345; 3,050,540; 3,050,541;3,077,490; and 3,100,786. Of these catalytic materials, those based onsodium are most preferable for use in accordance with this inventionbecause of their considerable effectiveness and generally lower cost.

The processes of this invention can be effectively used to prepare awide variety of different organoaluminum compounds including for examplehydrocarbon aluminum hydrides, hydrocarbon aluminum halides,trihydrocarbon aluminum compounds, and mixtures thereof. Thus theorganoaluminum compounds produced by the processes of this invention maybe depicted by the formula R R R AI wherein from 1 to 3 of R R and R arehydrocarbon radicals and the balance, if any, are halogen or hydrogen.Each hydrocarbon radical may contain up to 40 or more carbon atoms. Theinvention is particularly well suited for the preparation of alkylaluminum compounds, especially dialkylaluminum hydrides, or aluminumtrialkyls, or mixtures of both. However, the hydrocarbon radicalspresent in the products may be aryl, alkaryl, aralkyl, cycloalkyl or thelike.

The reaction conditions utilized in practicing the process of thisinvention are susceptible to considerable variation. For example whenemploying the present aluminum alloys to prepare organoaluminumcompounds by reaction among aluminum, organo aluminum compound andhydrogen with or without the co-utilization of olefin the reactiontemperature will generally fall within the range of about 90 to about170 C., temperatures between about 120 and about 150 C. being preferred.By the same token, the reaction pressures used in these processembodiments will generally be in the range of about 500 to about 5000p.s.i., with pressures of from about 700 to about 2500 p.s.i. beinggenerally preferred.

The proportions of the reactants are not critical although it isdesirable that there be an excess amount of hydrogen and of olefin (ifused) relative to the amount of aluminum contained in the reactionsystem.

Reaction times may likewise be varied to suit the needs of the occasion.Ordinarily, the reaction time may be in the range of about 5 minutes upto about 6 or 8 hours, or even longer if desired. However, for aneflicient commercial installation reaction times falling within therange of about minutes to about 3 hours are generally most suitable andare therefore preferred.

It is very desirable to provide ample agitation or turbulence in thereaction system to insure thorough mixing of the reactants and intimatecontact between the gaseous and liquid phases involved. If desired,suitable anhydrous solvents which do not adversely affect the desiredreaction may be employed. Exemplary of such solvents are saturatedaliphatic hydrocarbons (e.g., paraffinic hydrocarbons, cycloparaflinichydrocarbons, or mixtures thereof), aromatic hydrocarbons, saturatedfiuorocarbons, silicone oils, and other similar materials which areinert to the reactants and the organoaluminum product. It is feasible,although ordinarily not recommended, to conduct the reaction can bereadily controlled in the absence of such as amines, ethers, or the likeso long as there is an insufiicient amount of such material present tocomplex with all of the organoaluminum compound(s) initially present inthe system.

In preferred form the various process embodiments of this invention arecarried out in the absence of an ancillary solvent such as thosereferred to above. The reaction canb e readily controlled in the absenceof such solvents. Moreover, the lack of an ancillar solvent means thatthe reactors need not be sized to accommodate such materials.

As noted above, it is preferable to conduct the various processembodiments of this invention in the presence of an alkali metaladjuvant or catalyst. For best results, the alkali metal content of thesystem will generally be in the range of about 0.1 to about 2 percent byweight (expressed in terms of alkali metal although it will normally bepresent in the form of a chemical compound or complex) based on theWeight of the organoaluminum compound(s) initially present in thereaction system. Among the preferred catalysts for addition to thereaction system are metallic sodium, sodium hydride, sodium aluminumtetrahydride, sodium aluminum hexahydride, sodium fluoride, sodiumaluminum tetraalkyl, sodium aluminm dialkyl dihydride, sodim aluminumtrialkyl hydride, and the like, especially where the alkyl groups (ifpresent in the catalyst) each contain up to about 18 carbon atoms. Thecorresponding sodium aluminum aryls and cycloalkyls are also entirelysuitable. Indeed, lithium, potassium, rubidium and cesium are suitablecatalysts, whether charge into the system in metallic form or in theform of a chemical compound or complex corresponding to the sodiumderivatives already referred to. Mixtures of different alkali metals orcompounds thereof may be used.

For best results, clean, essentially anhydrous particulate aluminumalloys of the makeup described herein are employed. Inasmuch as thereaction should be conducted in an essentially anhydrous environment itis desirable to insure that the aluminum alloy feed to the process isitself free from excess moisture. In addition (the alloy should beessentially free from any oily residue, dirt, soil or other extraneouscontaminants which would tend to interfere with intimate contact betweenthe aluminum alloy and the other reactants being used.

Although the size of the particulate alloy is not critical, it isgenerally desirable that the particles range in size from fine particlesup to about 4 mesh. This enables the achievement of the most rapidreaction rates. It will be clearly understood and appreciated howeverthat even larger sized particulate aluminum "alloys may be successfullyused in the practice of this invention.

In order to demonstrate the practice and advantages of this invention,the following illustrative examples are presented.

EXAMPLE I An autoclave was charged with 75 ml. of triethylaluminum, 1gram of sodium, and 1 grams of aluminum alloy turnings having thefollowing composition:

Components: Weight percent Aluminum 86.68 Copper 3.50 Iron 0.50Manganese 0.50 Silicon 0.50 Chromium 0.30 Magnesium 2.50 Titanium 0.02Zinc 5.50

The autoclave was sealed and the contents heated to 140 C. under 2500psi. hydrogen pressure for about one hour. After discontinuing thereaction, the metallic residue was isolated, washed, dried and weighedandit was found that about 2.4 grams of aluminum had been consumed informing diethyl aluminum hydride.

EXAMPLE II The procedure of Example I was repeated except that thealuminum alloy turnings had the following composition:

Components: Weight percent Aluminum 86.99

Copper 3.50 Iron 1.00

Silicon 8.50 Titanium 0.01

In the course of this reaction about 2.9 grams of aluminum were consumedin forming diethyl aluminum hydride.

EXAMPLE III The procedure of Example I was repeated using turnings of analuminum alloy of the following composition:

Components: Weight percent Aluminum 95.09

Iron 0.25

Manganese 0.25 Silicon 0.25 Chromium 0.15 Magnesium 4.00 Titanium 0.1

The reaction resulted in the consumption of about 2.8 grams of aluminumand the formation of diethyl alumi num hydride.

6 EXAMPLE IV The procedure of Example I was applied to turnings of analloy of the following composition:

Component: Weight percent Aluminum 97.29 Iron 0.50 Manganese 1.00Silicon 0.50 Chromium 0.20 Magnesium 0.50 Titanium 0.01

Approximately 2.6 grams of aluminum was consumed in producing diethylaluminum hydride.

EXAMPLE V A reaction as in Example I was conducted except that the alloyturnings had the following composition:

Component: Weight percent Aluminum 86.75 Copper 3 .50 Iron 0.5 0Manganese 0.50 Silicon 0.50 Chromium 0.30 Magnesium 2.50 Zinc 5 .5 0

In forming diethyl aluminum hydride about 2.8 grams of aluminum wasconsumed.

EXAMPLE VI The procedure of Example I was repeated except that thealuminum alloy turns were produced from an aluminum scrap which analyzedas follows:

It was found that approximately 4.1 grams of aluminum was consumed informing diethyl aluminum hydride.

EXAMPLE VII The procedure of Example I was repeated except that thealuminum alloy turnings were prepared from an alummum alloy scrap of thefollowing composition:

Component: Weight percent Copper 0.3 Iron 0.8 Manganese 0.4 Silicon 1.5Chromium 0.6 Magnesium 1.5 Titanium u 0.03 Zinc 2.5 Lead 0.2 Nickel 0.05Silver 0.01 Aluminum and other impurities 92.11

The reaction resulted in the production of diethyl alu' minum hydrideand the consumption of about 3.1 grams of aluminum. It is interesting toobserve that when the procedure of Example I was applied to turningsmade from commercially available aluminum 99'.4 percent aluminum)essentially the same results were obtainedabout 3.4 grams of aluminumwas consumed in forming the diethyl aluminum hydride.

The organoaluminum compounds which can be prepared by the process ofthis invention are of known utility as ingredients for polymerizationcatalysts and as chemical intermediates in the production of olefins,alcohols, and other valuable products. For further details, referencemay be made to the patent literature, including the disclosures of theUS. patents cited above.

We claim:

1. In a process wherein an organoaluminum compound is produced byreacting aluminum with an organoaluminum compound (hereinafter defined)and hydrogen or with olefin and hydrogen in the presence of anorganoaluminum compound (hereinafter defined), the improvement whichcomprises employing as aluminum feed to the process an aluminum alloycontaining about 50 to 98 percent by weight of aluminum and at least sixof the following elements in the amounts shown:

Element: Weight percent Copper 0. 15 Iron 0.1-2.5 Lead 0. 11.5 Manganese0.05-3 Nickel 0.052.5 Silicon 0.1--10 Tin 0.05-1

the total quantity of said elements present being about 0.75 to 20percent by weight; the organoaluminum compound utilized in the processhaving the formula R R R Al wherein from 1 to 3 of R R and R arehydrocarbon radicals and the balance, if any, are halogen or hydrogen,each such hydrocarbon radical containing not more than about 40 carbonatoms.

2. The process of claim 1 wherein all of said elements are present inthe aluminum alloy.

3. The process of claim 1 wherein said alloy contains about 80 to 96percent by weight of aluminum.

4. The process of claim 1 wherein said total quantity is about 0.75 to12 percent by weight.

5. The process of claim 1 wherein said aluminum alloy contains about 80to 96 percent by Weight of aluminum and wherein said total quantity isabout 0.7 5 to 12 percent by weight.

6. The process of claim 1 wherein an alkali metal catalyst is employedin the reaction.

7. In a process wherein an organoaluminum compound is produced byreacting aluminum with an organoaluminum compound (hereinafter defined)and hydrogen or with olefin and hydrogen in the presence of anorganoaluminum compound (hereinafter defined), the improvement whichcomprises employing as aluminum feed to the process an aluminum alloycontaining about 50 to 98 percent of aluminum and at least six of theelements copper nickel Iron silicon Lead tin manganese the totalquantity of said elements present being about 8 0.75 to 20 percent, themaximum quantity of those of said elements present being as follows:

Percent Copper Iron 2.5 Lead 1.5

Manganese Nickel Silicon Tin 1 all of the percentages being expressed byweight; the organoaluminum compound utilized in the process having theformula R R R A1 wherein from 1 to 3 of R R and R are hydrocarbonradicals and the balance, if any, are halogen or hydrogen, each suchhydrocarbon radical containing not more than about 40 carbon atoms.

8. In a process wherein an alkyl aluminum compound is produced byreacting aluminum with an alkyl aluminum compound and hydrogen in thepresence of an alkali metal catalyst or with olefin and hydrogen in thepresence of copper iron lead manganese the total quantity of saidelements present being about 0.75 to 20 percent, the quantity of thoseof said elements present being as follows:

Element:

Copper Iron Weight percent 0.1-5 0.1-2.5 Lead 0.1-1.5 Manganese 0.05-3Nickel 0.05-2.5 Silicon 0.1-10 Tin 0.05-1

all of the percentages being expressed by weight.

9. The process of claim 8 wherein all of said elements are present inthe aluminum alloy.

10. The process of claim 8 wherein a sodium catalyst is employed in thereaction.

References Cited UNITED STATES PATENTS 5/1962 Ziegler et al. 9/1963 Raddet al. 7/1968 Ichiki et al. 260-448A FOREIGN PATENTS 1/ 1961 GreatBritain 260-448A TOBIAS E. LEVOW, Primary Examiner H. M. S. SNEED,Assistant Examiner U.S.C1.X.R. -139 j 9;

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,576,832 Dated April 2l l97l Inventor(s) Warren E. Becker and Paul;Kobetz It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 4, line 5 reads "organo aluminum", should read organoaluminum --5line 37 reads "action can be readily controlled in the absence of such",should read action 1 the presence of certain basic substances such line&5 reads "canb e readily", should read can be readily --3 line 68 reads"charge", should read charged Column line 71 reads "Titanium --O. 1',should read Titanium "-0.01 Column 6, line 20 reads "Aluminum --86.75",should read Aluminum -86.7O

Signed and sealed this Zhth day of August 1971.

(SEAL) Attest:

EDWARD M.FIETCHER,JR. WILLIAM E. SGHUYLER, JR. Attesting OfficerCommissioner of Patents

